1. University Center of Internal Medicine, Cantonal Hospital Baselland, 4410 Liestal, Switzerland
2. Faculty of Medicine, University of Basel, 4056 Basel, Switzerland
3. Clinic of Pneumology, Hospital of Valais, University of Geneva, 1205 Geneva, Switzerland
4. Department of Pulmonary Medicine and Allergology, University Hospital, University of Bern, 3010 Bern, Switzerland
5. Department of Pneumology, Claraspital, 4058 Basel, Switzerland
6. Department of Pneumology, University Hospital Zürich, 8091 Zürich, Switzerland
7. Clinic of Medicine, Department of Pneumology, Cantonal Hospital Münsterlingen, 8596 Münsterlingen, Switzerland
8. Division of Pulmonology, Department of Medicine, University Hospital Lausanne, CHUV, University of Lausanne, 1011 Lausanne, Switzerland